Hybrid Shear-Wall System for the Construction of Solid-Wood Buildings in Seismic Zones

ABSTRACT

A hybrid shear wall system for construction of massive timber buildings of more than two stories in seismic zones, is provided, which presents a ductile behavior and reduced overturning effect against a lateral load caused by destructive natural events, such as earthquakes or strong winds; the shear wall system comprises an interior frame with articulated nodes of union between columns and sills, to which exterior massive timber panels are joined on both opposite faces, by means of individual energy dissipating connectors; where the frame comprises post-tensioned self-centering means, which together with the articulated nodes, the exterior massive timber panels and the connectors, act together as a unit and allow the shear wall to behave in a ductile manner and with reduced overturning effect under high lateral load.

The invention is an application in the field of construction engineeringand specifically relates to a massive wood hybrid cutting wallstructural system for the construction of buildings of 5 or more floorsapplicable in seismic zones, which provides protection against extremeload events, such as ties or strong winds.

PREVIOUS ART DESCRIPTION

The earthquake's are unpredictable and sudden natural events, whichcause large human losses normally caused by the damage caused in theinfrastructure of a population. In some cases, the very strong winds,including the cyclones, can also cause movements in buildings andstructural damage.

In the latter decades, the work has been increased in the design anddevelopment of construction systems for concrete and steel buildings ofvarious floors for regions subject to seismic activity, lookingprimarily to prevent catastrophic failure of the building and protectlife.

The different problems derived from the occurrence of an earthquake, interms of infrastructure damage, have led to construction technologiesthat allow the construction of buildings capable of withstandingearthquake without structural damage, in order to reduce the economiccost of building repair and/or reconstruction, as well as minimizing thetime of inactivity in the use of the in furniture during such repair orrepair periods after an earthquake or any other destructive event.

There are several factors which, in recent years, have led to searchingfor different construction solutions to the use of steel and concrete,which not only meet the structural requirements of the materials, butalso have an important reduction in the time of construction, the costsand the environmental effects that are derived from the differentbuilding techniques.

In that sense, such factors have been relevant in the increase in theuse of frame wood panels (lightweight wood framing) and the use ofmassive or solid wood panels, such as cross laminated wood (CLT) panels,vertically laminated veneer panels (LVL) and parallel strand Wood panels(PSL) in construction and construction projects of more than two orthree floors. One of the main advantages of construction with this typeof wood panels is the low weight that they have and therefore exhibitreduced design forces; on the other hand, construction with this type ofpanels allows for an accelerated line of building time as compared toconventionally used construction materials and processes, and can bereduced from months to just weeks. This is greatly enhanced becauseconstruction with this type of wooden panels allows for a line ofprefabricated materials that can be conceived in specialized spaces forthis and then transported to the area of the construction where they aremounted.

An additional factor that is driving the increase in the demand forwooden panels in construction projects is the difference in the fieldlabor types required; the construction of a structure with wooden panelsof this type requires general specialization workers or workers, whiletraditional multi story construction projects that, use concrete andsteel require specialized labor in concrete finishes and swingers,generally at higher operating rates than the characters and workers ofgeneral specialization.

Another factor that has driven not only the demand for panels madeentirely of wood for buildings, but also the demand for mixed panels,with frames of prefabricated concrete or steel materials and normallywith wood veneer sheathing, is the environmental benefit from thecleaning in the construction, the waste and the recycling capability ofthe materials, which in the case of construction with prefabricatedwooden panels or steel frames it is more clean and completelyrecyclable; in both the traditional construction with reinforcedconcrete in situ in situ, it involves a process that is quite dirty,leaves many waste, and in terms of recycling capability, it presents alarge problem, since if the seam is recyclable, concrete is not,requiring an expensive and complex destruction process to achieve theseparation of two different materials and to recover the flashing in theevent that the demolition of the building is carried out.

This type of composite panel based construction can be seen as describedin U.S. Pat. No. 3,975,510 (B2) of Miller, C, which discloses astructural panel system for use in lightweight construction, typicallyof a floor or two; in that case, although the disclosed panels are mixedby the use of an inner frame which may be wood or metal coated by woodenplates on each side and joined by screw type connectors this type ofsystems does not allow construction of more than two floors used ascutting walls, as by the thicknesses of the materials, the framing ofthe frame and mainly by the connecting means, it is seen that they arefor low load stress structures with low, seismic resistance.

In particular, this type of systems use very thin wood plates, 11 to 15mm. If they are of OSB or plywood, where that thickness is notsufficient to embed connectors of diameters that generate a sufficientlyductile and strong connection capable of dissipating energy. Thus, themain disadvantage of this type of light systems is that they do notpossess structural capability for building seismic loads of 5 to 10floors.

In the foregoing, other construction systems have been developed fortesting seismic events, where the use of thicker wooden panels offeringmuch greater strength capabilities has been sought, which are notequivalent to the use of boards Like the OSB or plywood, but havethicknesses greater than 60 millimeters, such as cross laminated wood(CLT cross laminated tiber).

This is seen in Japanese patent application JP2018080569 (A) published24 May 2018 Of Saadahiiro Osu, the al which proposes a large wall ofwood, which is aimed at preventing brittleness, through a wall comprisedof vertically stacked CLT panels, but separated by a dilation, each ofthe high half of the interfloor, there is a top attached to an upperbeam of a steel frame by a high strength connection, and there isanother lower panel joined to a lower beam of the frame, respectively bythe same connection; in this case, the energy dissipation comes from aplate, like connector element coplanar between the two wall panels,which is designed with a lower resistance than the joints between theCLT panels and the steel beams. The disadvantage or problem with thissolution is that all the working of the CLT is concentrated in a singlelocation, i.e, the entire transmission of the cut and the dissipation isconcentrated in the coplanar connector element disposed between the twopanels so as to work a small portion of the CLT panels, making itunreliable; it is also seen that there are different types ofconnections, one between the panels of the CLT to the frame and theother between said panels the energy dissipation scheme in this patentis the plate type connector of the medium which concentrates all of thedeformation and cutting, since the upper junctions are many with gluedsteel bars, they do not dissipate energy.

In various solutions of this type, the problem arises that the steelframe used and the CLT are two resistant systems that work in paralleland do not form a single system; the steel frame primarily resistsvertical forces while the CLT wall resists lateral forces, so that inthis type of structures the gravitational system is separated from TheCLT, specifically in this newly cited document are large beams whichcarry the loads to the columns, this is evidenced by noting that the CLThas a dilation and is separated, therefore it does not transmit verticalload.

On the other hand, this type of system does not address the liftingproblem, so that they do not offer solutions that avoid the effect ofrollover or rocking and in the case of this Japanese patent the mainsteel structure is used, that frame is which transfers the moment androllover, Does Not do the CLT, which requires dimensionally importantbeams, making them in a low cost and cost efficient system. When a steelframe is the main structure, and operating the CLT alone as a bracingdevice at lateral forces to give rigidity to the main frame, it is amuch more flexible system and therefore, with a lack of sufficientrigidity so as to resist large seismic forces and to meet the structurewith a displacement or drift (which is the maximum horizontaldeformation allowed between two floors in a seismic event) as set forthin construction standards in most territories of high seismicconcurrence.

In the prior art, some solutions are known that point to solving theproblem of the dumping effect and hence the problem of the interstorydisplacement that is produced by cars, such as the use of tendons whichare seen in German Patent application AU201577979 (al) published 15 Jun.2015 of Murray Parkson, L, where a Connecting system for walls stackedin height of a building is described, which enables post tensioning saidwalls. This system uses the CLT and a series of arrays by means of steeltubes and cables which have the characteristic of providing resistanceto lateral forces (wind and sism). This document contains arrangementsthat help solve the problem of tilting or dumping the CLT panels, butdoes not quantify how much helps to improve the ductility.

On the other hand, the most important disadvantage is that it is afairly elaborate system, then requires the manufacture of many specialparts that are possibly quite expensive when they wish to be used in abuilding that is located in a high temperature area. It requires manypieces and steel components to be manufactured with very good precision,i.e, it requires specialized manufacturing, to ultimately assemble allthis in the wall requiring many in situ labels that do not lack theconstruction. Placing all of the above in walls of buildings in a highseismic area, where most of them are arranged as cutting structuralwalls, and each of them requires all of these tubes and steel pieces tobe very costly. Therefore, it is believed that this may be of utility inzones of low stress, where only a few walls are required to be cutstructural.

The construction based on massive wooden panels, such as cross laminatedwood panels (CLT), have as a main feature that are self-supporting andallow for the rapid prefabrication of dwellings and buildings, beingused in slabs, ceilings and as cutting walls in order to obtain morerigid structures.

In structural engineering, a cutting wall is a structural systemcomprised of rigid wall panels to counteract the effects of lateralloading in the plane acting on a structure. The wind and the seismicloads are the most common loads that the cutting walls are designed toresist.

By virtue of various construction standards, the designer is responsiblefor designing an appropriate amount, length and arrangement of thecutting wall lines in both orthogonal directions of the building tosecurely resist imposed lateral loads. The cutting walls can be locatedalong the outside of the building, inside the interior of the buildingor in a combination of both.

When a cutting wall is subjected to a rollover or rocking force, theconnectors and anchors distort and this rollover force imposes ahorizontal displacement in the lateral system or vehicle. The strengthof the wood cutting walls is an important factor in determining theresponse of the cutting walls to the wind and the seismic forces; alower resistance, the greater the rollover effect.

Thus, during a seismic load event or other type of high intensityloading, the cutting walls can be balanced towards one side or towardsthe other, and back independently, under the influence of the lateral orhorizontal force. In any event, the cutting walls are offset from sideto side around its point of attachment to the support of the base, i.e,on their respective ties to the support of the base. The independentwall roll allows for the damping of movement or dissipation of energy inthe connectors, either connecting connectors between adjacent panels orjoint connectors between a panel and its inner structural frame.

In connection with the problem of the dumping effect of the cuttingwalls, the effect known in the rubro as a rocking joint, this rotationconcentrates the damage to the lower anchors, which causes the collapseof the wall and the tile to collapse. In turn, this rigid rotationgreatly increases the lateral displacement of the floors, whichincreases the deformation of the floor (drift).

There are seismic design standards of buildings, where this industrydefines the value of the seismic response factor (R) and the maximumvalue of the interfloor displacement of the structures (the interfloordisplacement is the maximum horizontal deformation allowed between twofloors in a seismic event); while, the R coefficient is a factor thatbasically allows to decrease the seismic forces with which it isdesigned such that the greater the greater, the greater the structurecan be reduced and the cheaper the structure. Detailing a little plusthis concept, the design force is said to be equal to the elastic force(which depends on the weight of the structure and its rigidity) startingfrom the R Value, ie:

Design force=elastic Force/R

Thus, the greater the Value of R, the lower the design force.

In highly seismic zones there are very demanding standards of seismicbuilding design, which makes the CLT and similar wood structures to havea very low seismic response factor (R), implying that the forces withwhich a building must be designed will be greater and therefore muchmore expensive. It is also possible that the maximum value of theallowed interfloor displacement is very discrete (only a 2 percent inhighly seismic countries) which indirectly forces the wall systems to bevery rigid in order to meet this requirement. This is a non-minorproblem in conventional wooden structures, because they are moreflexible. Given the relative low capacity in axial loading ofconventional wooden walls (frame type type), it occurs that buildingsconstructed with wood must employ a large number of walls.

The main difficulty of CLT walls is the problem of rigid body rotationcaused by its flexible structural nature, which is defined as beingrigid enough to resist large seismic forces, so that a building withthis type of prefabricated walls completely based on The CLT wouldinvolve the use of a high amount of walls, facing the system.

Throughout the foregoing, there is a need for a cutting wall system thatallows for medium height buildings in wood for highly seismic zones,achieving increasing the reduction factor of the Seismic design R forconstruction with wood; so that if the axial loading capacity isincreased with respect to conventional wooden walls using the CLT, theamount of cutting walls necessary and significantly reducing theconstruction costs can be greatly reduced.

Thus, the present invention is directed to a cutting wall system with afunctionally integrated hybrid configuration of mass wood panels againstCLT laminated and an inner frame of another material different from thatof said panels, wherein said structure exhibits a high capacity toresist lateral load, greater rigidity, greater ductility and the abilityto dissipate energy than conventional wooden panels, has reduced effectof in addition, the lateral displacement of the floors is significantlydecreasing and decreasing the seismic forces with which it is designed,makes it economically competitive.

DESCRIPTION OF THE INVENTION

The present invention relates to a hybrid cutting wall system for theconstruction of massive wooden buildings of more than two floors inseismic zones, which exhibits a ductile behaviour, rigidity and reducedrollover effect against a lateral load caused by destructive naturalevents, such as collisions or strong winds.

The invention is a cutting wall system which, using massive wood as oneof its essential components, allows to reach a height of buildings ofmore than 2 floors with a lower number of walls than that which requireother structural wooden systems, with increased ductility and ability todissipate energy, without rigid rotations that concentrate the damage tothe main anchors, and economically competitive.

The present invention is intended to propose a rigid cutting wall systemand highly resistant to seismic loads, based on mainly a hybridstructure of massive wood panels and an inner frame formed by othermaterials other than the mass wood, wherein both the frame and thewooden panels act concomitantly as a single system.

It is another object of the invention to provide a cutting wall systemhaving a high concentrated ductility in a high energy dissipation effectof the system, achieving that the load is distributed evenly along theentire perimeter of the cutting wall.

Still another object of the invention is to provide a cutting wallsystem which allows for a significant reduction in the rollover effect,avoiding the lifting and displacement of the walls, resulting in agreater stiffness and reduction of the maximum value of the interfloordisplacement.

Another object of the invention is to provide a cutting wall systemwhich allows to reduce rehabilitation costs subsequent to the seismicevent, achieving that the integrity is not compromised in damage to thegravitational load bearing elements.

Thus, the present cutting wall system comprises a hybrid structure, withan articulated inner frame and massive wooden outer panels joined toboth sides of the frame, forming a sandwich type structure, wherein thepanels are joined to the frame by means of individual power dissipatingconnectors and where the inner frame comprises articulated connectingnodes between columns and solders conforming to the frame.

The cutting wall further comprises self-centering means consisting ofpost tensioned tensioners arranged along the wall and preferably only atthe lateral edges of the wall, which are associated only to the columnsor alternatively, associated with the columns and to the ends of theplates together. This relationship and the operation of theself-centering means will be explained later.

The inner frame is formed from columns and columns, where the columnsare a set of vertical loading pillars which at least comprises two endside columns each located at each of the side edges of the cutting wall.

This column assembly may further include at least one intermediatecolumn disposed between the two ends; the presence of this intermediatecolumn will depend on the dimensions of the cutting wall, so that ashallow wall constructed with a single mass wooden panel could not needan intermediate column, rather if the wall is of a length where at leasttwo wooden panels are required adjacent to each other, the intermediatecolumn is arranged just where the joint joint is coincident between saidadjacent panels, so that the energy dissipating connectors, whichconnect the wooden panels to the frame, have an anchoring support.

Each of the columns, are end or intermediate sides, are formed by avertical body which may be solid or tubular, preferably of rectangularcross section, in which an upper minor face, a lower face, an outerlongitudinal face, an inner longitudinal face and opposite front facesof each other are defined.

The end side columns, in particular, comprise means of passing said posttensioned tensioners, which lie inside and along its longitudinal axis.These pitch means may consist of longitudinal channels extending fromthe upper lower face to the lower face of the column, where this channelbased solution is especially applicable in cases where the columns aremade of a solid material, such as wood or concrete but in the case ofbeing tubular bodies, such as a tubular steel profile, these columnsneed not add channels, but the tensioners freely pass through the cavityof the profile.

In alternative embodiments said side columns may comprise two, three,four or more longitudinal channels whereby they traverse said posttensioned tensioners.

Following the description of the structure of the inner frame, it isintended to comprise a top sill and a lower hearth, wherein each of themis formed by a horizontal body which can be solid or tubular, preferablyof rectangular cross section, where lower lateral faces, an outerlongitudinal face, an inner longitudinal face and front longitudinalfaces opposite one another are defined.

These plates may comprise at least two transverse channels through whichthey traverse said post tensioned tensioners, so that in an alternativeembodiment, said rods lack these channels, depending on theconfiguration and material of manufacture of the frame.

Thus, the configurations that the inner frame may take to dependprimarily on the material used; in one embodiment of the inner framewith tubular steel profiles, the upper and lower plates acquire thetotal width of the wall, where the inner longitudinal face of said uppertile rests against the upper lower faces of the columns, while the lowerfaces of the columns are abutting on the inner longitudinal face of thelower tile.

In this case, since they are tubular profiles, the post tensionedtensioners freely pass within the profile conforming to the columns, butto traverse the plates and allow the tensioners to protrude from theupper and lower edges of the wall, such welds must include, in each endarea, channels or transverse openings extending between its innerlongitudinal face and the opposite outer longitudinal face.

This configuration of the inner frame may also be applied in the eventthat columns and containers are made of concrete, but in this case,since the parts are a solid body, it is necessary for said columns tocomprise at least one longitudinal channel to allow the at least onepost tensioned tensioner to pass, while the blanks must comprise, ineach end area, transverse channels extending between its innerlongitudinal face and its opposite outer longitudinal face.

In one embodiment of the inner frame made with columns and woodenflooring, given the flexibility of the material it is necessary to avoidcrushing the upper edge of the columns, so that the plates are placedinside the side columns, thus, the latter are extended by the overallheight of the wall. Specifically, the lateral minor faces of the upperdeck lie in abutment with an upper area of the inner longitudinal faceof the side columns, while the lower lateral sides of the lower hearthlie in abutment with a lower area of the inner longitudinal face of theside columns. This configuration of the inner frame may also be appliedin the event that columns and containers are made of concrete.

In embodiments as just described, since columns and containers are solidbodies, in order to pass the post tensioned tensioners, the sametreatment must be followed as the concrete pieces, ie, it must beprovided with longitudinal channels in the columns to allow thetensioners to pass.

Thus, in any of the frame configurations just described, it is possibleto add an intermediate column, which would have the same conditions asthe side columns; although in a preferred alternative embodiment, theintermediate column does not comprise longitudinal channels for thetensioners, since that piece is practically not working.

In a final configuration of the frame, the assembly of the front andmiddle side faces form the support surfaces where the heat sealableconnectors are anchored or fixed to each of the mass wooden panels withthe inner frame. These energy dissipating connectors are individualelements together, which are installed throughout the perimeter of thepanel. It is to be understood that if the wall comprises two massivewooden plates adjacent one side of the other, then the frame comprisesat least one intermediate column where the heat sinks are fixed.

The mass wood panels, such as the CLT, are relatively rigid andtherefore energy dissipation must be achieved by the ductile behaviourof the connections between different elements of the cutting wall.Therefore, high load strain capability connectors are needed thatprovide a high ductility or hysteretic energy dissipation to achieveacceptable performance of bulk wood panel buildings during events suchas earthquake or large wind loads.

In the present invention, the heat sink connectors are of metal, of thetype pin, selected from the group of pins, screws and nails. Forattachment of the CLT panel to a steel frame, the connectors arepreferably self-piercing pins. Thus, when the frame is wooden orconcrete, the connectors are preferably threaded screws throughout itslength. The function of the self-drilling connectors is to bracing theframe with respect to the seismic cutting force. The connectors are theweak point of the structure, so that the failure is intentionallyproduced there, which allows for much ductility until the ultimatefailure is reached.

The essential feature of the system relating to its hybrid wallcondition is given because, as mentioned above, the inner frame is of amaterial other than the material of the massive wooden panels that arefixed outwardly. Thus, the columns and columns of the frame are of amaterial that can be selected from materials such as steel profiles,post tensioned concrete or laminated wood.

In the case of being steel, they are tubular profiles, preferably with aresistance from ASTM a −36 to ASTM a −53 (240 to 365 MPa). If they areconcrete, they preferably comprise a compressive strength in the rangeof 20 to 35 MPa, where the end side columns are of post tensionedconcrete. While if they are wood, they are laminated, with a strength ofthe range between 1.3E and 1.55 The invention is characterised in thatit is preferably made of LSL (rolled Strand) or MLE (Rolled wood) or LSL(Laminated wood) Laminated wood.

In terms of the outer panels of the cutting wall, they are structuralwooden panels, preferably the panels are of bulk wood against laminated(CLT) with a thickness between 60 mm and 100 mm. It is important thatthe panels be thick, such as the CLT of thickness between 60 to 100 mm,because they offer much greater strength capabilities, since byconnecting the CLT to the frame, the length of connector remainingwithin the CLT panel is greater than when compared to the embeddedlength thereof within a typical OSB Or plywood (plywood) board. Theimportance of using a thick panel, as in this case the CLT, makes itsuse not equivalent to the use of any board, because the CLT given itsthickness of 60 to 100 mm is achieved by embedding the connector (screw,pin or long pin) inside it, and achieves that it forms a plastic jointat the interface of the frame with the CLT as the wall is deformed andthe CLT Is slid relative to the steel frame.

But in terms of the requirement for a thick thickness of the outerpanel, it is not attainable with any thick panel of massive woodavailable on the market, such as, for example, the LVL (Rolled Veneerlight), which would appear Equivalent to the CLT.

The LVDT is produced by gluing wooden sheets together in a largemolding, which is then serrated to the desired dimensions depending onthe constructive application, however the plates are glued such that thedirection of the fiber or grain of the wood is arranged in a singledirection, the direction of the longitudinal or longer axis of thestructural element, this implies that it only has an important strengthin the longitudinal axis thereto fit is therefore only efficient forload stresses in a single direction.

In contrast, the CLT consists of several layers of wood boards stackedand glued together transversely or orthogonal (typically glued at 90degrees), because it resists loading stresses in both the longitudinaldirection of the element and the transverse direction, which determinesthat it can take cutting loads, and not only the axial directions. If itis thought in walls of both materials in a building, the LVL walls canonly take up for example vertical axial loading of the structuralweight, rather the CLT walls can take both loads, vertical andhorizontal by wind or sism. Accordingly, they are not intended to betechnically equivalent materials, because the CLT addresses anotherstructural need; in this sense the CLT may not Be replaced by the LVDTfor an application as the proposal in this invention since the sameresult would not be achieved.

The frame materials connected to the CLT generate lower crush strengthand regulate the frangible effect that can cause a traditional CLT wall.The utility of the LVDT and other materials is to coordinate andreinforce the stress produced at the joints. Bulk woods Such As GLT(Glulam), LSL microlaminated woods, LSL Are Materials that counteractthe side loading effect in a single direction, rather than in the otherdirection are weak. The wood in general has much greater strength andrigidity in the direction of the fibers. The CLT panels have fibersoriented in both directions within the plane.

Given the foregoing, the invention proposes this sandwich cutting wallstructure to provide improved seismic performance. The elements of thewall frame support the axial load, also the stress between the CLTpanels connected to the frame generates greater resistance to cutting.The above depends on the type of joints to which the wall truss isconnected, ie, the joints between columns and solders.

Therefore, another of the essential characteristics of this cutting wallsystem is that the inner frame is articulated, which is given becausethe points of attachment between welds and columns are articulated nodetype assemblies, consisting of a normally pivoting mechanical attachmentmeans that allows for assembly with relative movement in a plane betweensaid columns and said plates.

By arranging this type of joints in the structure of the inner frame, itis achieved that the rigidity and lateral strength of the wall isdominated by the outer panels of massive wood.

This allows a master prediction of stresses in the components andespecially at the joints, so that the structural design and itsexperimental response can be accurately predicted with great precision.

The connection of the articulated joints remains in an elastic regime,limiting the rigid body displacements. Thus, the predominant deformationfor non-limbed walls is clearly shear so that the capacity and rigiditycan be assumed proportional to the length of the wall.

If the columns and welds are of steel profiles, the mechanicalattachment means conforming to the articulated nodes preferably consistsof a pair of rigid support plates parallel to each other traversed by atransverse connecting pin.

If the columns and tanks are wooden, then the mechanical attachmentmeans conforming to the articulated nodes preferably consists of asupport lug attached to the columns, and on which the ends of the platesare seated. The plate can be fixed to the column by means of a diagonalpin so as to permit articulated movement between them.

If the columns and containers are of concrete, then the mechanicalattachment means conforming to the articulated nodes may consist of aseat bracket projecting laterally from the columns, forming integralpart thereof, as a single piece or as an added part, and on the bracketthe ends of the concrete solders are seated, and adding a pin allowingrelative movement between the pieces, in a single plane.

Another of the essential characteristics of this cutting wall system arethe self-centering means, which allow the structure of the wall toacquire rigidity in an elastic regime which reduces the lifting effectof the wall, decreasing the feasibility of rocking laterally, and inturn allows the structure to be received after receiving a high lateralload stress, the structure is restored by acquiring its originalposition.

The self-centering means of the proposed cutting wall consists ofnon-adhered tensioners whose position goes to the height of the cuttingwall, allowing an elastic attachment of the wall with a foundation orother wall stacked on one another in a coplanar position.

These tensioners comprise a lower end and an opposite upper end, wherethe lower end may be anchored and embedded in a foundation, whichhappens in the bottom or base cutting wall in a building; oralternatively, the lower end is axially adjustable to a wall connectorbetween walls allowing for the postulated adjustment of the lower end ofan upper wall stacked on the upper end of a bottom wall.

Therefore, the upper end of the tensioners can be fixed, but in anaxially adjustable manner, to a wall/wall connector, which allows forthe postulated adjustment of the lower end of an upper wall stacked onthe upper end of a bottom wall; or said upper end may also be fixedaxially, axially adjustable, to an anchor plate located on the upperedge of a wall, on the base to which the tensioner is post assembled.

The tensioners may be non-stick, spun steel bars with adjustablefasteners at their ends of the anchor plate type, or may be toron,non-stick, wedge shaped, wedge and anchor plate type steel cables.

In an exemplification of the assembly of two cutting walls stackedtogether, according to the present invention, it would be seen that afirst cutting wall is disposed on a foundation and, for example, thewall comprising an inner frame of steel profiles, wherein the upper andlower plates extend along the entire width of the wall, then the lowertile of this first wall has simple attachment means with saidfoundation, such as anchor bolts distributed along it; thus, the sidecolumns contain inside the self-centering tensioners, where the lowerend thereof is concreted to the foundation and the opposite upper end isattached to a coupling connector which allows for the axial connectionbetween said tensioners and at the same time between the first wall andthe second wall disposed stacked on the first.

Thus, this second wall is mounted in a coplanar manner to the first,sill with the sill, allowing the tensioners of the first wall to extendtowards the second from the nipple connector, where the upper end of thetensioner is fixed to the upper edge of the second wall in an anchorplate. Alternatively, in low height buildings, the tensioners could becontinuous elements from the foundation to the upper edge of the topwall, regardless of the coupling of the coupling between walls. On theother hand, the walls may account for lateral anchoring means of the keytype of cutting.

In operation, the frame structure is subjected to a permanent elasticrate which is stiffened with the structural involvement of the woodenpanels once they are connected to the frame by means of the heat sinkconnectors, wherein these wooden panels serve the function of bracingthe load elements of the inner frame, in addition to meeting theresistance to axial load function in cooperation with the same frame,both elements acting as a single system.

The desired effect, within the combination of the CLT materials in theouter panels; steel, concrete, LSL or LVL, in the Inner frame, togetherwith the joints between the columns and solders conforming to the frame,plus the post tensioned tensioners located at the end edges of the wall,which in conjunction with the structure in an elastic regime; rather theenergy dissipating connectors, allow for a ductile behaviour of the walland at the same time rigid in comparison to the usual walls constructedof wood in general.

Thus, it is possible to describe more precise mode, how it is thebehavior of each of the cutting wall components that is reason of thepresent invention: the CLT panels provide rigidity and lateral strength,subjected to simple cut stresses; the inner frame serves as a mechanismthat allows the lateral load of the floor to be translated to the woodenpanels, where their articulated nodes allow the frame to move laterallywithout opposition, the entire strength and stiffness being attributedto the outer panels of wood. On the other hand, the post tensionedtensioners prevent the lifting of the rigid body on the driven side ofthe wall, and in conjunction with the anchors of the lower sill, alsoprevent lateral displacement of the wall; the heat sink connectors whichjoin the outer panels with the inner frame permit the bracing action ofthe CLT panels, and function as the weak part of the system in such away that they prevent the breaking of the panels, frame or othercomponents.

In the cutting wall system of the present invention, the deformationdoes not occur by tipping of the wall but by the cutting of the panels,and especially the cut in the connectors which join the panels to theinner frame. Said cutting deformation is much more advantageous becauseit allows to avoid additional deformations of the rigid body and inparticular causes the capacity and rigidity of the wall is linearlyproportional to its length, resulting in a much more predictable andcontrolled mechanical behaviour.

Another advantageous property is that a void intermediate space isachieved between the two CLT panels where the thermal insulation can beplaced in the same manner as in a platform frame. In this system it ispossible to put the insulation inside, while in walls made entirely ofconventional CLT, screws and a termination must be installed to fix theinsulation outside, since when a solid board is not possible to put theinsulation. Another greatly notable advantage of this system is that itis possible to place the installations (plumbing, electricity, etc.)inside the wall, as well as the platform system. In the conventional CLTthe installations are much more complicated to incorporate into thewalls.

This system is cheaper than a conventional wall. In general, the CLTwalls are sized according to the seismic load to be supported. In thisway, the following example may be shown based on the Chile seismicDesign Standard:

In a conventional CLT wall

a) the next volume of wood is occupied: 100 mm thick, 2.4 m high and 2.4m wide=0.576 m3 of wood.b) the typical resistance is 75 KN.c) that is to say 75 KN/0.576 m3=130 KN of strength per m3 of wood.d) the above is regardless of the reduction factor of the seismicresponse. Now well, considering that for the Conventional CLT R=2, it isgiven that the design force that the wall is able to resist is 130×2(=R)=260 KN/m3. That is, if it is to resist a force of 260 KN in a CLTbuilding, the Chilena NCh433 is allowed to reduce the force by 260/R=130KN, which implies that it can actually resist 260 KN of lateral force(seismic) per m3 of wood that would occupy.e) the anchors that are required are typically two lock down pins andfour keys (cut angles).

In the present invention of wall with CLT

a) 2 plates of 60 mm=120 mm thick, 2.4 m high and 2.4 m wide, i.e, 0.691m3 of wood are typically occupied. Assuming square feet of cross sectionlaminated wood, 24 cm×9 cm and a total length of 10.8 m (2 sols of 2.4 mand 3 feet right of 2 m) we can take up to occupy 0.24×0.09×10.8=0.23 m3of wood in the inner frame. That is, it would be occupied by occupying0.691 M3 in CLT+0.23 m3 in laminated wood=0.921 m3 of wood per wall.b) the typical resistance is 220 KN.c) 220 KN/0.921 m3=239 KN/m3 of wood are obtained.d) considering that it is more likely that the R=5.5 as the platformframe (actually being modifying The R of the platform frame by 6.5), weobtain that 239×5.5=1315 KN of lateral force can resist each m3 of wood.e) the anchors required are typically 2 steel cables and severalanchoring bolts.

From the foregoing it can be concluded that, in one way, that with theconventional system it can typically be withstood 130 KN per m3 of woodbeing occupied, while with the present invention it can be able towithstand 239 KN per m3 of wood being occupied, ie, the new system wouldallow to resist an 84% more force per m3 of wood used (almost double).However, the above is regardless of the fact that the constructionstandards (eg, the chilena NCh433 standard) allow to increase the forcethat can resist a wall if it is ductile.

Assuming that the present invention can occupy the R factor of aconventional platform frame, the system could withstand a force of 1315KN per m3 of wood, while a conventional wall (with much less ductility)could resist 260 KN/m3, i.e, the invention in practice should be able toresist a more. This implies that a building with this system wouldrequire only ⅕ (20%) of the types of wood requiring a conventionalsystem in walls. The costs of the slabs are typically 50% of the coarse,and the cost of the walls is the other 50%, which implies that thebuilding should occupy 100% wood in slabs and 20% wood in walls, i.e,the costs of the building as to the wood should be as 60% of aconventional building (so that it is effectively much cheaper).

The above is only considering the costs of the wood, but the joints mustalso be considered. The hold down buttons that are to be employed in theconventional CLT are very expensive (the Sizes XXL are required), whilein this system steel cables would be employed. With respect to thecutting keys of a conventional wall, these are clearly more expensivethan the anchoring bolts used in this system.

Throughout the above, it is estimated that the prices of the anchors inboth systems are similar. Moreover, the system of the present inventionemploys more screws, nails or bolts, as compared to the conventionalsystem, that is to attach the boards to the inner rigid frame. Thesecosts depend on the specific connector employed, but for example thelarge nails are very inexpensive. Throughout the foregoing, the proposedsystem is clearly much cheaper.

The joints may be somewhat more expensive (by the number of nails/screwsto be used) but the anchors are nearly the same. However, the volume ofwood that would be occupied would be much less. In particular, the useof more nails is used to be much more split to the material, and thatmakes it easier.

DESCRIPTION OF THE DRAWINGS

A detailed description of the invention will be carried out inconjunction with the figures which form an integral part of thisembodiment, wherein:

FIG. 1 shows an isometric exploded view according to a first embodimentof the cutting wall.

FIG. 2 shows a front elevational view of the first embodiment of thecutting wall.

FIG. 3 shows a front elevational view of a second embodiment of thecutting wall.

FIG. 4 shows an exploded, exploded isometric view of the secondembodiment of the cutting wall.

FIG. 5 shows an isometric view in partial exploded view of the secondembodiment of the cutting wall.

FIG. 6 shows a side elevational view of the first embodiment of thecutting wall.

FIG. 7 shows a front elevational schematic view of an example assemblyof two cutting walls stacked together.

FIG. 8 shows an isometric view of the first embodiment of the reinforcedcutting wall.

FIG. 9 shows an exploded isometric view of the second embodiment of thecutting wall.

FIG. 10 shows an exploded isometric view of the first embodiment of thecutting wall.

FIG. 11 shows a side elevational view of the second embodiment of thecutting wall.

DETAILED DESCRIPTION OF THE INVENTION

With reference to the figures which form an integral part of thisembodiment, and thus as illustrated by way of example in FIG. 1 , thepresent invention relates to a hybrid cutting wall (1) system for theconstruction of massive wooden buildings of more than two floors inseismic zones, which exhibits a ductile behavior and reduced rollovereffect against a lateral load caused by destructive natural events, suchas strong winds or winds.

The invention comprises an inner frame (100) with hinged (120)connecting nodes between columns (120) and solders (130), to which theouter mass (200) panels are joined at both sides by means of individualenergy dissipating connectors (300), wherein the frame (100) comprisespost tensioned self-centering means (400), which in conjunction with thearticulated nodes (110), the outer mass wooden panels (200) and theindividual energy dissipating connectors (300) they allow the cuttingwall (1) to behave in a ductile manner and with reduced rollover effectagainst a high lateral load.

Taking as example, FIG. 2 , the columns (120) conforming to the frame(100) comprise end side columns (121) containing at least one innerlongitudinal channel (122) by which they traverse the self-centeringmeans (400). The columns (120) further comprise at least oneintermediate column (123), and wherein each of the columns (120)exhibits an upper lower face (124), a lower face (125), an outerlongitudinal face (126), an inner longitudinal face (127) and oppositefront faces (128).

Now, in reference to FIG. 3 , in this configuration the welds (130)conforming to the inner frame (100) comprise an upper hearth (131) and alower hearth (132), which contain at least two transverse channels (133)whereby they pass through said self-centering means (400). The solders(130) comprise minor lateral faces (134), an outer longitudinal face(135), an inner longitudinal face (136) and opposite front longitudinalfaces (137). In another configuration, as seen in FIG. 2 , the welds(130) are arranged between the columns (120), and therefore lacktransverse channels for the passage of the self-centering means (400).

As shown in FIG. 4 , the articulated nodes (110) of the inner frame(100) comprise a pivoting mechanical attachment means that allows forassembly with relative movement in a plane between said columns (120)and the solders (130). This mechanical attachment means conforming tothe articulated nodes (110) may consist of a set or pair of rigidsupport plates (111) parallel to each other traversed by a transverselink pin (112) where each set of the platens (111), as seen In FIG. 5 ,can be fixed to the inner longitudinal face (136) of the plates (130)and then between the platens (111) each column (120) attached to thefront faces (128) of said columns.

Alternatively, the mechanical attachment means may consist of a supportlug (not shown) attached to the inner longitudinal faces of the columns,on which the ends of the plates are seated. Yet another alternative mayconsist of a seat bracket (not shown) projecting laterally from thecolumns, on which the ends of the plates are seated.

Now, in abutment with that illustrated in FIG. 6 , the self-centeringmeans (400) comprises non adhered tensioners (401), with a lower end(402), an opposite upper end (403) and arranged along the cutting wall(1). The can be non-stick, spun bars or toron, non-stick, type steelcables.

As best illustrated in FIG. 7 , in the assembly of two cutting walls (1)(G), the lower end (402) of the tensioners (401) is anchored embedded ina foundation (A) when it is treated from the lower cutting wall (1) ofthe first floor, but also, when the upper cutting wall (G) is treated,the lower end (402′) of the tensioners (402′) may be fixed, althoughaxially adjustable, to a coupling connector (B), where this connector(B) allows for the attachment of the tensioners (401), (401′) betweenstacked walls. The upper end (403) of the stiffeners (401) of the lowerwall (1) is fixed, but is axially adjustable, to the coupling connector(B); or said upper end (403′) of the brackets (401′) of the top wall (G)is fixed axially to an anchor plate (D) at the upper end of the sameupper wall ( ).

The lower deck (132) of the lower wall (1) can be attached to thefoundation (A) by means of anchoring bolts (E), which are the same withwhich the lower wall (132′) of the top wall (G) is attached to the topsill (131) of the bottom wall (1); additionally, the walls (1), (G) canconsider means of lateral fixing of the key type of cutting (EF).

As seen in FIG. 8 , the power sinks comprise a plurality of individualelements, each of which are attached to each of the outer mass (200)panels with the articulated inner frame (100), which are installedthroughout the perimeter of the panel (200). These may be pin type metalconnectors selected from the group of pins, screws and nails, preferablyself-piercing pins and threaded screws throughout the entire lengththereof.

The inner frame may take different configurations depending primarily onthe material used; in one embodiment of the inner frame with tubularsteel or concrete profiles, as illustrated in FIG. 9 , the upper (131)and lower (132) solders acquire the total width of the wall, where theinner longitudinal face (136) of said upper tile (131) abuts against theupper lower faces (122) of the columns (120) while the lower faces (125)of the columns (120) about the inner longitudinal face (136) of thelower hearth (132).

In another embodiment of the inner frame, as illustrated in FIG. 10 ,such as shown in FIG. 10 , such as of the type made with columns andwood flooring, the plates (130) are located inside the columns (120),thus, the latter are extended by the overall height of the wall;specifically, the lateral minor faces (134) of the plates lie inabutment with the inner longitudinal face (127) of the side columns(121). In the event that the wall configuration also comprises anintermediate column (123), the lower lateral faces (134) of the platesare also of stop to the sides of this intermediate column. Thisconfiguration of the inner frame may also be applied in the event thatcolumns and containers are made of concrete.

As seen in FIG. 11 , preferably, the outer panels (200) are laminatedAgainst laminated (CLT) wood panels with a thickness between 60 mm and100 mm, the columns (120) and welds (130) conforming to the inner frame(100) may be steel Profiles with a resistance from ASTM a −36 to ASTM a−53 (240 to 365 MPa), may be of concrete with a compressive strength inthe Range of 20 to 35 MPa or may be of laminated wood with a strength ofthe range between 1,3E and 155E.

1. Hybrid shear wall system (1) for construction of massive woodbuildings of more than two stories in seismic zones, which presents aductile behavior and reduced overturning effect against a lateral loadcaused by destructive natural events, such as earthquakes or strongwinds, wherein it comprises an interior frame (100) with hinged nodes(110) for connection between columns (120) and sills (130), to which areattached exterior massive wood panels (200) on both opposite sides, bymeans of individual energy dissipating connectors (300); where the frame(100) comprises post-tensioned self-centering means (400), whichtogether with the articulated nodes (110), the exterior massive woodpanels (200) and the connectors (300), act together as a unit and allowthe shear wall (1) to behave in a ductile manner and with reducedoverturning effect against a high lateral load.
 2. Hybrid shear wallsystem (1), according to claim wherein the columns (120) forming theframe (100) comprise extreme lateral columns (121) including at leastone longitudinal channel (122) through which said self-centering means(400) pass.
 3. Hybrid shear wall system (1) according to claim 2,wherein the columns (120) further comprise at least one intermediatecolumn (123), and wherein each of the columns (120) comprise an upperminor face (124), a lower minor face (125), an outer longitudinal face(126), an inner longitudinal face (127) and facing faces opposite eachother (128).
 4. Hybrid shear wall system (1) according to claim 1,wherein the sills (130) forming the inner frame (100) comprise an uppersill (131) and a lower sill (132), which contain at least two transversechannels (133) through which said self-centering means (400) pass. 5.Hybrid shear wall system (1) according to claim 4, wherein the sills(130) comprise lateral minor faces (134), an outer longitudinal face(135), an inner longitudinal face (136) and front longitudinal facesopposite each other (137).
 6. Hybrid shear wall system (1) according toclaim 1, wherein the articulated nodes (110) of the inner frame (100)comprise a pivoting mechanical joint means allowing an assembly withrelative movement in a plane, between said columns (120) and said sills(130).
 7. Hybrid shear wall system (1) according to claim 6, whereinsaid mechanical connecting means conforming to the articulated nodes(110) consists of a pair of rigid support platens parallel to each othercrossed by a transverse connecting pin.
 8. Hybrid shear wall system (1)according to claim 6, wherein said mechanical joining means conformingto the articulated nodes (110) consists of a support block attached tothe columns (120), on which the ends of the sills (130) are seated. 9.Hybrid shear wall system (1) according to claim 6, wherein saidmechanical connecting means conforming to the articulated nodes (110)consists of a seat bracket projected laterally from the columns (120),on which the ends of the sills (130) are seated.
 10. Hybrid shear wallsystem (1) according to claim wherein the self-centering means (400)comprise unattached turnbuckles (401), with a lower end (402), anopposite upper end (403) and are arranged at the top of the shear wall(1).
 11. Hybrid shear wall system (1) according to claim 10, wherein thelower end (402) of the turnbuckles (401) is anchored embedded in afoundation (A).
 12. Hybrid shear wall system (1), according to claim 10,wherein the lower end (402) of the turnbuckles (401) is fixed in anaxially adjustable manner to coupling connector (B) between walls (1).13. Hybrid shear wall system (1) according to claim 10, wherein theupper end (403) of the turnbuckles (401) is fixed in an axiallyadjustable manner to a coupling connector (B) between walls (1). 14.Hybrid shear wall system (1) according to claim 10, wherein the upperend (403) of the turnbuckles (401) is fixed in an axially adjustablemanner to an anchor plate (D).
 15. Hybrid shear wall system (1)according to claim 10, wherein the turnbuckles (401) are spun bars,non-adherent, with adjustable fasteners at their ends of the anchorplate type.
 16. Hybrid shear wall system (1), according to claim 10,wherein the turnbuckles (401) are stranded, non-adherent,post-tensionable steel cables with wedge and anchor plate type. 17.Hybrid shear wall system (1) according to claim wherein the energydissipating connectors (300) comprise individual elements with respectto each other linking each of the outer massive wood panels (200) to thehinged inner frame (100), which are installed around the entireperimeter of the panel.
 18. Hybrid shear wall system (1) according toclaim 1, wherein the connectors (300) are metal connectors of the doweltype, selected from the group of pins, screws and nails.
 19. Hybridshear wall system (1) according to claim 18, wherein the connectors(300) are preferably self-drilling dowels.
 20. Hybrid shear wall system(1) according to claim 18, wherein the connectors (300) are preferablythreaded bolts throughout.
 21. Hybrid shear wall system (1), accordingto claim 1, wherein the exterior panels (200) are structural wood panelschosen among cross-laminated mass timber (CLT) panels, OSB boards orPlywood panels, as longus they have a thickness of at least 60millimeters.
 22. Hybrid shear wall system (1), according to claimwherein the panels (200) are preferably of massive cross-laminatedtimber (CLT) with a thickness between 60 mm and 100 mm.
 23. Hybrid shearwall system (1), according to claim wherein the columns (120) and thesills (130) forming the articulated inner frame (100) are steel profileswith a resistance from ASTM A-36 to ASTM A-53 (240 to 365 MPa). 24.Hybrid shear wall system (1), according to claim 23, wherein preferablythe steel profiles are tubular of rectangular section.
 25. Hybrid shearwall system (1), according to claim wherein the columns (120) and theslabs (130) forming the articulated inner frame (100) are made ofconcrete with a compressive strength in the range of 20 to 35 MPa. 26.Hybrid shear wall system (1) according to claim 25, wherein the extremelateral columns (121) are made of post-tensioned concrete.
 27. Hybridshear wall system (1), according to claim 1, wherein the columns (120)and the sills (130) forming the articulated inner frame (100) are madeof laminated wood with a strength in the range between 1.3E and 1.55E.28. Hybrid shear wall system (1) according to claim 27, wherein thecolumns (120) and sills (130) are, preferably of reconstituted laminatedstrand lumber (LSL) or glued laminated laminated lumber (MLE).